Notes

2013-06-19: The vertical datum of the 1998 TWDB rating curve for Lake Graham has been adjusted from NGVD29 to NGVD29+1.3ft.

Lake Graham: 77.5% full as of 2023-03-28

The elevation-storage rating curve used to produce the storage hydrograph is made of two segments: (1) the segment up to the conservation pool top (below the red line) is based on measured data, and (2) the segment in the flood pool (above the red line) is an extrapolation from the first segment and shouldn't be relied upon for flood storage information.

Historical Data

Date Percent Full Mean Water Level
(ft)
Reservoir Storage
(acre-ft)
Conservation Storage
(acre-ft)
Conservation Capacity
(acre-ft)
Surface Area
(acres)
Today 2023-03-28 77.5 1,070.61 35,108 35,094 45,288 2,142
Yesterday 2023-03-27 77.5 1,070.62 35,129 35,115 45,288 2,143
2 days ago 2023-03-26 77.6 1,070.63 35,151 35,137 45,288 2,144
1 week ago 2023-03-21 77.2 1,070.54 34,958 34,944 45,288 2,137
1 month ago 2023-02-28 76.5 1,070.39 34,638 34,624 45,288 2,126
3 months ago 2022-12-28 77.8 1,070.67 35,236 35,222 45,288 2,147
6 months ago 2022-09-28 81.8 1,071.50 37,061 37,047 45,288 2,204
1 year ago 2022-03-28 82.9 1,071.73 37,577 37,563 45,288 2,220
*

Percent Full is based on Conservation Storage and Conservation Capacity and doesn't account for storage in flood pool.

**

   Values above, including today's are averaged conditions. For near real-time instantaneous water level, see table below or the interactive map viewer.

Most Recent Instantaneous Water Level

Date/time Water Level
(ft)
Conservation Pool Elevation
(ft)
Height Above Conservation Pool
(ft)
Most recent 2023-03-28 12:00 1,070.61 1,075.00 -4.39
1 hour prior 2023-03-28 11:00 1,070.60 1,075.00 -4.40
2 hours prior 2023-03-28 10:00 1,070.59 1,075.00 -4.41
6 hours prior 2023-03-28 06:00 1,070.62 1,075.00 -4.38
12 hours prior 2023-03-28 00:00 1,070.61 1,075.00 -4.39
24 hours prior 2023-03-27 12:00 1,070.61 1,075.00 -4.39
48 hours prior 2023-03-26 12:00 1,070.64 1,075.00 -4.36
*

Data is provisional and subject to revision.

Additional Information

Impoundment date 1958-01-01
Gauge USGS:08088400
Vertical datum NGVD29 +1.3
Dead pool elevation 1,030.00 ft above NGVD29 +1.3
Service spillway crest elevation 1,076.30 ft above NGVD29
Top of dam elevation 1,093.30 ft above NGVD29
Conservation pool elevation 1,075.00 ft above NGVD29 +1.3
Data download (CSV) period of record, last one year, last 30 days

Elevation-Area-Capacity Curves

1958-01-01 (source: USGS)
1998-04-01 (source: TWDB) : GIS Data

Lake Location